There has been considerable activity in the blow molding of bottles constructed of thermoplastic materials such as polyethylene and polypropylene. These bottles are conventionally blow molded and then filled. Finally they are capped. Most of the prior art has dealt with such bottles wherein they are sealingly capped at a much later date after filling.
Of fairly recent vintage is the concept of blow molding a bottle in a conventional manner and then filling the bottle with a fluid material while the bottle is retained in the mold. The bottle is integrally sealed with thermoplastic material after filling. The seal is usually a breachable membrane or a cap which may be broken away along a weakened part line. The attractiveness in this manner of fabrication resides in the fact that the contents in the bottle are admitted when sterile and are then sealed therein in a sterile condition. The bottle has not been exposed to ambient conditions prior to filling so that organisms have not had the opportunity to invade the interior of the bottle.
The mode of operation and the apparatus therefor of a prior art technique can be seen in U.S. Pat. No. 3,325,860. This patent discloses the general concept of blow molding and filling a thermoplastic bottle prior to integrally sealing. The present invention is an ingenious improvement over such prior art disclosure.